A Dallas County grand jury has declined to indict a Parkland Memorial Hospital psychiatric technician who was fired in July after investigators said he choked a patient unconscious.

Parkland police submitted the case — containing a videotape that captured the incident — to the office of Dallas County District Attorney Craig Watkins late last year for possible prosecution. The recording showed tech Johnny Roberts “placing his hand on complainant’s throat and choking the complainant until he loses consciousness and falls to the floor,” according to a police report obtained by The Dallas Morning News.

Watkins’ office declined to comment on the panel’s finding. “Due to the fact the case was no-billed by the grand jury, it would not be appropriate,” a spokeswoman said. Parkland officials also declined to discuss the matter. Efforts to reach Roberts for comment were unsuccessful.

Last year, the U.S. Centers for Medicare & Medicaid Services found that Parkland violated the rights of the patient, whose identity has not been disclosed by Parkland or law enforcement authorities to protect his privacy. Parkland police records show that another tech, David McClarron, used “excessive force” on the same patient, but the investigators did not request that the DA review his actions for prosecution.

It is the second time in the last seven months that Parkland police have submitted a case to the DA alleging patient abuse by psych techs and a grand jury declined to issue indictments.

The hospital’s psychiatric department has been under heavy scrutiny by CMS and state regulators for months. The News reported in November that Roberts and McClarron were among several psych techs whom Parkland kept on the job despite abuse allegations.

Roberts was among a group of psych techs who mishandled psychiatric patient George Cornell shortly before he died last February. After The News disclosed Cornell’s death, CMS concluded his rights were violated when techs used illegal restraint maneuvers.

Ensuing inspections found life-threatening dangers throughout the hospital. Parkland is now under a rare form of federal safety supervision.

The police records do not say what led to the patient’s choking, but a CMS report obtained by The News does: The man was sitting in a chair, waiting to have his blood drawn, when a drink was “snatched” from his hand.

“The patient jumped up,” according to the report, which summarizes what an inspector found when investigating the matter. “Two technicians sat him down in the lab chair. The patient became aggressive, attempting to hit both techs.”

That’s when Roberts put the man in a choke hold.

“The patient continued to be combative and then suddenly his face turned red and he went limp, sliding down the chair,” the report said.

After a nurse assessed him on the floor, the patient regained consciousness and tried to attack the techs again. They physically restrained him, injected him with a drug for agitation and put him in solitary confinement.

According to the federal report, the man gave Parkland police this statement two months after the incident: “After being asked to have blood drawn, I was soon being held on the ground. As best my memory serves, I was grabbed from a chair and thrown to the floor. A heavy amount of weight as well as a very hard grab was applied.”

Hospital officials met with the man’s mother and later sent her a letter verifying that “an employee restrained your son in an inappropriate manner.”

The News requested a copy of the video last summer. But the Texas attorney general’s office allowed Parkland to withhold it because a criminal investigation was pending.